1. Field of the Invention
An embodiment of the present invention relates to a pixel and an organic light emitting display device having the same, and more particularly, to a pixel that can stably maintain the voltage of the data signal stored in a storage capacitor, while sufficiently securing the capacity of the storage capacitor, and an organic light emitting display device having the same.
2. Description of the Related Art
Recently, various flat panel display devices that have light weight and small volume compared to a cathode ray tube have been developed.
Among the flat panel display devices, an organic light emitting display device displays an image using organic light emitting diodes that are self-light emitting elements which are advantageous in brightness and color over traditional display devices, making them the next generation display device.
The organic light emitting display device as described above is divided into a passive matrix organic light emitting display device and an active matrix organic light emitting display device according to the scheme by which the organic light emitting display device is driven.
Among others, the active matrix organic light emitting display device includes a plurality of pixels positioned on intersections of scan lines and data lines, wherein each pixel includes an organic light emitting diode and a pixel circuit that drives the organic light emitting diode. Such an active matrix organic light emitting display device is advantageous in view of small power consumption, high resolution, and large area compared to the passive matrix organic light emitting display device.
The pixel circuit of the general active matrix organic light emitting display device includes a switching transistor that transfers a data signal to the inside of the pixel when a scan signal is supplied, a storage capacitor that stores the data signal transferred to the inside of the pixel, and a driving transistor that supplies the driving current corresponding to the data signal to the organic light emitting diode.
The organic light emitting diode emits light at the brightness corresponding to the driving current from the driving transistor. Therefore, in order for the organic light emitting diode to emit light at a constant brightness during the emission periods of the respective frames, the data signal stored in the storage capacitor of the respective pixels should be stably maintained, and have a predetermined value, during the emission period of the corresponding frame.
However, recently, as the resolution of the organic light emitting display device increases, it is becoming more difficult to design space for forming the pixel circuit.
Therefore, there is an increased demand for a method for effectively using the limited design space.
Moreover, for the normal emission of the pixel, there is demand for sufficiently securing the capacity of the storage capacitor effectively using the given space and there is further demand for stably maintaining the voltage of the data signal stored in the storage capacitor.